1. Field of the Invention
The present invention is related to novel engine fuel additives which are more efficient and environmentally safer than the relatively higher boiling naphtha and/or naphthalene containing engine fuel additive products. The inventive fuel compositions are suitable for igniting internal combustion engines and diesel engines, as well as jet propulsion engines.
2. Description of the Prior Art
The performance of an internal combustion engine may be adversely affected by the formation of deposits in or around the fuel injection system and combustion chamber. Even when present in minor amounts, these deposits, resulted from incomplete combustion, can cause a noticeable reduction in the performance of the engine, an increase in fuel consumption, and the production of exhaust pollutants. It is generally accepted that deposit formation is largely dependent on the fuel composition, and to a lesser extent, on the engine design and on the operating conditions of the engine. In an effort to control deposit formation, considerable efforts have been directed toward developing fuel additives that could facilitate the complete combustion of fuel, thereby reduced the tendency to cause the formation of deposits. In particular, the majority of the research has been directed toward developing fuel additives that either prevent or reduce the formation of such deposits.
For example, it has been proposed to employ various alkyl ethers, as fuel additive, for the purpose of dissolving deposits generated by gasoline fuels. Such attempts are described in U.S. Pat. Nos. 2,089,580, 2,104,021, 2,221,839, 2,563,101, 2,786,745, 2,930,681, 3,032,971, 3,103,101, 3,270,497, and 5,425,790 as representative. As described in those patents, it is frequently the practice to employ such ethers either alone or in combination with alcohol to provide improved performance characteristics in a variety of liquid hydrocarbon fuels.
U.S. Pat. No. 5,912,189 discloses compositions that are useful as fuel additives for reducing intake valve deposits. Such compositions comprise the reaction product of: (a) a cyclic compound containing at least one nitrogen and at least one carbonyl group; (b) an aldehyde or ketone; and (c) an etheramine.
U.S. Pat. No. 5,873,917 discloses compositions that are useful in reducing intake valve deposits. Such compositions contain: (a) a polyether alcohol; (b) a hydrocarbonphenol; and (c) optionally, a nitrogen-containing dispersant.
U.S. Pat. No. 5,514,190 discloses fuel additive compositions for controlling intake valve deposits. These compositions comprise: (a) a gasoline-soluble Mannich reaction product of a high molecular weight alkyl-substituted phenol, an amine, and an aldehyde; (b) a gasoline-soluble poly(oxyalkylene) carbamate; and (c) a gasoline-soluble poly(oxyalkylene) alcohol, glycol, or polyol, or mono or diether thereof.
U.S. Pat. No. 5,697,988 discloses a fuel additive composition that reduces engine deposits and controls octane requirement increases in engines. The fuel additive composition comprises: (a) a Mannich reaction product of a high molecular weight alkyl-substituted phenol, an amine, and an aldehyde; (b) a polyoxyalkylene compound; and (c) optionally, a poly-.varies.-olefin.
U.S. Pat. No. 4,818,250 further discloses other alternatives to conventional fuels, including U.S. Pat. No. 4,131,434 to Gonzalez, which is directed to a fuel additive for oil, diesel oil, and gasoline to improve fuel efficiency and reduce resulting air pollutants. Exemplary Gonzalez additives are aromatic and aliphatic hydrocarbon solvents with and without oxygenated functional groups, terpenes, and aromatic nitrogen containing compounds.
U.S. Pat. No. 2,402,863 to Zuidema et al., which is also discussed in the Whitworth patent, is directed to blended gasoline of improved stability and, more particularly, leaded gasoline containing up to about 10% alicyclic olefins which preferably contain a cyclohexane ring. Cyclic olefin is defined as an alicyclic hydrocarbon containing an olefin double bond in the ring (preferably no more than one). The alicyclic olefins are suggested to be available from terpenes or from synthesis such as partial dehydrogenation of naphthenes. A number of individual cyclic olefins are stated as being suitable, including, for example, terpenes such a di-limonene (citene) and D-limonene (dipentene).
In an article, “Acetone in Fuels”, published by SmartGas (Jul. 29, 2006), Louis LaPointe stated the presence of acetone in the fuel could cause the fuel to burn better. Acetone survives the heat of combustion for a very long time although it vaporizes readily. While it burns slowly, its fierce vibrations break apart the massive fuel fragments that surround it. So, acetone encourages greater vaporization, thus leads to a much better mileage. LaPointe further concluded that acetone and ortho-xylene not only improve mileage, but also cut pollution dramatically and give longer life to engines.
Despite such efforts, further improvements in the art are needed. Specifically, what are needed are fuel additives that function as fuel surface tension softener that lubricates the parts, as well as prevents or reduces deposit formation in the port fuel injected internal combustion engines. Fuel compositions containing such fuel additives also facilitate a full combustion within the combustion cycle, therefore reduces toxic emissions, such as carbon monoxide and nitrogen oxides.